Embodiments of the present invention relate to an apparatus and method for environmentally testing a device in situ. More specifically, embodiments of the present invention relate to an apparatus and method for environmentally testing a printed circuit board coupled to a motherboard.
Before devices are produced en masse and offered for public use, they generally undergo different types and degrees of testing. One type of testing that may be performed is environmental testing or environmental qualification. In environmental testing, the device is exposed to different conditions to determine how the device will perform under those conditions. Typically, the device is exposed to conditions more extreme than those the device will actually experience during normal operation.
Electronic devices such as printed circuit boards used in computer systems may undergo environmental testing for temperatures outside of the expected range of normal operating temperatures. Conceivably, a printed circuit board could be placed in an oven and subjected to high and low temperature extremes, then placed into a computer system to determine if the printed circuit board remains functional. However, such a test procedure does not provide information regarding how the printed circuit board performs while actually subjected to the temperature extremes.
Therefore, it is desirable to environmentally test the printed circuit board with the board in place and functional on a motherboard. Generally speaking, according to prior art test procedures, the printed circuit board is installed on the motherboard along with other components needed to make the motherboard/printed circuit board combination functional, in essence constituting a rudimentary computer system. The rudimentary computer system is placed inside a test chamber such as an oven or refrigerator, which can be heated and/or cooled as needed for the environmental testing. Different operations and functions that utilize the printed circuit board can then be performed, and information characterizing the performance of the printed circuit board under the environmental test conditions can be gathered and analyzed. At some point, due to either the extreme operating conditions or the prolonged exposure to those conditions, the rudimentary computer system may cease to function properly.
Prior art procedures for environmental testing of printed circuit boards suffer from a number of disadvantages. One disadvantage is highlighted by the above discussion. That is, for some reason, the rudimentary computer system may cease to function; however, without further investigation, it is not possible to determine if the device under test (e.g., the printed circuit board) failed, or if some other component (also subjected to the test environment) of the rudimentary computer system failed. The motherboard itself typically includes a number of components, any of which may have failed during the environmental testing. Consequently, it may be necessary to install the printed circuit board in another computer system to determine whether or not the board is still functional. If the printed circuit board is functional after the test, this would indicate that another component had failed. This may render the environmental test as inconclusive because, for example, the other component may have failed before the testing of the printed circuit board was completed. The testing then needs to begin anew, generally with all new components.
Therefore, another disadvantage of the prior art is that quantities of other components are consumed during the environmental testing. As mentioned, components other than the device under test may fail during testing. Even assuming that this is not the case, the components used in a test are likely unusable for subsequent tests. The amount of life remaining in previously used components is unknown. Should there be a failure during another environmental test, it would not be possible to know immediately whether the device under test or some other component failed, as described above. Thus, after a test is performed, whether the test is successfully completed or not, the components used in the test are often discarded. This can increase tremendously the hardware costs of environmental testing, especially when multiple tests are performed.
Other disadvantages of the prior art include the inconvenience and expense of the test chambers themselves. Many such chambers may be used for conducting tests in parallel, and there is a cost associated with acquiring and maintaining the chambers as well as with providing the space needed to use and store the chambers. Also, the configurations of some test chambers make it difficult to set up the test. For example, test personnel may find it difficult to wire monitors and probes to the device being tested once the device has been placed inside the test chamber.
Thus, what is needed is a test apparatus and/or method that can address the problems summarized above. The present invention provides a novel solution to these problems.
Embodiments of the present invention pertain to an apparatus for environmental testing of a device under test (DUT), such as a printed circuit board. The apparatus generally includes a chamber for environmentally isolating the DUT with the DUT in situ and functional on another device (e.g., a motherboard). The DUT can be subjected to an environmental test condition (e.g., a prescribed maximum or minimum temperature) inside the chamber while the other device is isolated from the environmental test condition. The chamber may have a connector for coupling the other device and the DUT, such that the DUT and the other device are in communication although in isolated environments.
In one embodiment, a regulating assembly for producing the environmental test condition is coupled to the chamber. In one such embodiment, the regulating assembly is automatically powered off when the environmental test condition meets a threshold.
In one embodiment, a processor is coupled to the regulating assembly. The processor can control the regulating assembly to effect the environmental test condition. In another embodiment, a redundant controller is coupled to the regulating assembly. The redundant controller also can control the regulating assembly to effect the environmental test condition.
In yet another embodiment, a display monitor is used for displaying information pertaining to the environmental testing. In one such embodiment, the display monitor is coupled to the DUT (e.g., to the printed circuit board). In another such embodiment, the display monitor is coupled to the other device (e.g., to the motherboard).
In one embodiment, the chamber is configured to manage condensation within the chamber (e.g., to keep condensation from accumulating and/or from making contact with the DUT).
In summary, embodiments of the present invention provide a test apparatus, and method thereof, that allow the DUT (e.g., a printed circuit board) to be environmentally tested while in place on another device (e.g., a motherboard), but with the other device (e.g., the motherboard) isolated from the test environment. Thus, should there be a failure during testing, the device under test can be quickly identified as the likely failure point. In addition, other devices used in the testing can be used in subsequent tests. This not only reduces the costs associated with testing, but also enhances the repeatability of test results by reducing the number of new variables introduced from test to test. Furthermore, by virtue of its reduced size relative to conventional test chambers, a test apparatus in accordance with the embodiments of the present invention is expected to be more convenient and less expensive to use.
These and other objects and advantages of the various embodiments of the present invention will become recognized by those of ordinary skill in the art after having read the following detailed description of the embodiments that are illustrated in the various drawing figures.